I've spent a little time trying to find anything to suggest that more male Blackbirds migrate here than females but nothing I've read seemed to suggest this. Apparently a lot of Scottish and northern English birds migrate too with more females leaving than males. So maybe the 'Majorca hypothesis' reflects some truth.Perhaps our local female birds do leave for the winter.I've no idea. I also find that about 90% of my local Blackbirds in winter are male.
Glad to see some records from Tregroes.I have to drive down the Cerdin valley once a week for work and it's a nice way to finish a round. Higher up the valley,nearer to Bwlch y Groes, is a good spot for Marsh Tit.The road squeezes between Pont y Bargoed and Lestys and I've seen Marsh Tits on their garden feeders a few times, indeed just a week or two ago I did.